Mathematical and physical modelling of pipe flow of settling slurries

Abstract

Presented study deals with investigation of two phase flow composed of water and settling solid particles. The main contribution is a set of results of experiments, carried out in pipe loops at the Institute of Hydrodynamics of the Academy of Sciences of the Czech Republic, and at the Faculty of Civil Engineering of Czech Technical University in Prague. The experiments were focussed to ability of flow to convey solid fraction and on effect of solid fraction on flow friction, particularly in the case of flow above eroded surface of stationary deposit formed at the pipe bottom. Experimental methodology and results are reported. Special attention is paid to evaluation of concentration profiles by means of radiometric density meter which was employed to extend available database on inner structure of settling slurry flows in pipes. Obtained findings on specific flow aspects are implemented in a predictive model for stratified flow in pipes. The model performance is discussed on the base of comparison of model predictions with measured data. Results on friction at strongly eroded surface of granular bed would be applicable not only in pipes with deposit but also in the field of river hydraulics.

Presented study deals with investigation of two phase flow composed of water and settling solid particles. The main contribution is a set of results of experiments, carried out in pipe loops at the Institute of Hydrodynamics of the Academy of Sciences of the Czech Republic, and at the Faculty of Civil Engineering of Czech Technical University in Prague. The experiments were focussed to ability of flow to convey solid fraction and on effect of solid fraction on flow friction, particularly in the case of flow above eroded surface of stationary deposit formed at the pipe bottom. Experimental methodology and results are reported. Special attention is paid to evaluation of concentration profiles by means of radiometric density meter which was employed to extend available database on inner structure of settling slurry flows in pipes. Obtained findings on specific flow aspects are implemented in a predictive model for stratified flow in pipes. The model performance is discussed on the base of comparison of model predictions with measured data. Results on friction at strongly eroded surface of granular bed would be applicable not only in pipes with deposit but also in the field of river hydraulics.